1. Field of the Invention
This invention pertains to the field of food aromatization capsules and more specifically to foamed aromatization capsules. In particular, the present invention is concerned with the preparation of capsules having improved aroma retention and having improved means of delivering the retained aroma constituents to the user of the product in which these capsules are contained.
2. Description of the Prior Art
The desirability of retaining the flavor and/or aromatic constituents of food materials for a considerable length of time without their loss or deterioration has long been recognized.
In the preparation of instant coffee, for example, attempts have been made to incorporate the aroma principles of freshly roasted coffee by spraying them onto the surface of dried coffee extract as an emulsion with coffee oil. Careful sealing of the container for the aromatized dried coffee is required, however, to prevent escape of the aroma. After the container is opened, though, it is not too long before the aroma is lost in any event.
Encapsulation of aromatic constituents has also been investigated. Such an encapsulation technique is disclosed in U.S. Pat. No. 3,989,852 issued to Palmer.
Palmer prepares capsules by first forming a viscid, pasty core medium. This core medium contains the aromatic constituents to be encapsulated and has a tacky consistency which is somewhat akin to unhardened fudge with only a very small percentage of liquid contained therein. This core is then added to an agitated film-forming agent which adheres to the core medium to form the capsules.
This and similar techniques may suffer from a number of disadvantages. The amount of encapsulated aroma in such a technique is rather low and thus undesirably necessitates the addition of a relatively high proportion of such capsules to the host product which is to be aromatized. Moreover, these capsules do not retain the aromatic constituents for a considerable length of time when placed in the host product. This loss of aroma may be attributable to the final capsule structure which is generally comprised of a continuous solid phase throughout the capsules without there being any clearly defined capsule wall or shell to help retain the aroma within the capsules.
Most importantly, however, when water is added to the host product containing such capsules so as to reconstitute the same as in, for example, instant coffee, instant tea, instant soup, etc., the aromatic constituents contained within these capsules are generally not released from the reconstituted product immediately, so that the consumer does not perceive a burst of aroma when these capsules rupture and dissolve. Instead, due to the very large ratio of water employed in comparison to the amount of aromatic constituents contained within the capsules and because the capsules generally tend to sink to the bottom, the major portion of the aroma is simply dissolved in the water without ever leaving the cup. The concentration of the aromatic constituents is generally such that practically none of these constituents are present in the vapor phase at the surface of the cup in a concentration which is sufficient to produce an aroma which the consumer can immediately sense as in-cup aroma.